Howling front axle

Hi guys, a friend of mine has a 95 grand cherokee with the dana 30 up front. This thing howls pretty bad at hiway speeds. Starts making noise around 35mph and gets very annoying at 55. Definately coming from the front. Sounds like a bad bearing to me. I drove it with the front driveshaft off and it didn't go away. Also rotated the tires to make sure it wasn't that. Pulled the front diff cover and fluid was clean and no shavings. I went to pull the hubs but one of the bolts looked like it was gonna snap so I left it alone. There is no play in the hub bearings, so I'm not sure where to look next. Any input is appreciated.

Regards,

SimpleXJ

My 2001 XJ had a similar problem. I thought it was the transfer case at first but eventually found it was a combination of problems. The front hubs were tight but they made a growling noise. Once replaced, another noise could be clearly heard from the front axle. Found that both carrier bearings were toasted. Once replaced, the noises disappeared. YMMV

Yup, it definitely sounds like the front diff. carrier bearings are toast.
Are you sure you didn't find a wolf trapped inside the diff. carrier?

If the howling changes pitches, it is your pinion bearing.

One quick test I´ve found usefull, is to put it in 4X and listen to it in drive and reverse. If it´s the pinion or the carrier bearings, the sound changes. It is often louder in reverse. Check it at full turn, noise gets worse, it´s often the front axle U-joints, it will often clack, clack, clack a little.
Grab the pinion yoke and shake it up and down vigoursly, you can usually feel the play, also the seal often seeps.
Put a pry bar under the carrier and lift it a few times, you can see the play at the carrier bearings, most times. A few thousandths isn´t gonna hurt much, usually a lot more than that when they get loud.
Put it up on jack stands (under the axle) and turn the steering wheel all the way left (and right) rotate the tire by hand (at turn lock), you can usually see, feel and hear if the axle U-joints are loose.
If the axle U-joints arn´t making noise, rotate the axle with the tire and disc off, holding the center of the hub, you can feel a slight grinding (dry bearings) in the hub.

Thanks guys. I checked the axle ujoints and they are good. Will do the pinion bearing test with the prybar tomorrow when its light out. I had a similar problem in a '98 I used to have but it was in the rear axle. This is a first for me on the dana 30. Thanks for the help all

Regards,

SimpleXJ